The BBC's accurate report summarises the findings of a trial in which 80 adults with attention deficit hyperactivity disorder (ADHD) were given either capsules containing a mix of vitamins and minerals (micronutrient formula) or a placebo every day for eight weeks.

Researchers compared the participants' symptoms on various different mental health scales over time. They found that, compared with placebo, the micronutrient formula significantly improved the scores by a small amount on some assessment scales.

This was a well-conducted trial, but:

it was too short for anyone to be able to say whether these vitamins and minerals will help adults with ADHD in everyday life in the long term

the treatment involved taking 15 capsules every day, which may be an unacceptable amount for people to take

micronutrients were only compared with a placebo, not with existing standard treatments for ADHD

no children with ADHD were studied, so we can't say if micronutrients could help them

As the researchers say, it's a start: micronutrients seem OK for adults with ADHD symptoms, and they may do some good.

Where did the story come from?

The study was carried out by researchers from the University of Canterbury, the University of Otago, and Canterbury District Health Board in New Zealand, and was funded by the Vic Davis Memorial Trust.

What kind of research was this?

This was a randomised controlled trial investigating the safety and effectiveness of a broad-based micronutrient formula in treating ADHD in adults. The formula contained mainly vitamins and minerals, but no omega fatty acids.

The role of nutrition in ADHD is hotly debated. However, the researchers say that treatments have tended to focus either on restricting food items from the diet or supplementing the diet with only one nutrient at a time.

The researchers say that ADHD is estimated to affect between 4 and 5% of adults. ADHD that persists into adulthood often responds poorly to ADHD medication compared with children. Adults with ADHD also often have other mental health conditions, such as depression or a substance misuse problem, which further reduces response to treatment.

This study therefore aimed to examine the effects of a broad-spectrum micronutrient formula, EMPowerplus – said to have been previously researched for the treatment of various other mental conditions – in adults with ADHD not taking any medication.

An RCT is the best way to examine this question, although there may be some limitations around sample size, duration of treatment and the outcomes measured. The larger and longer a RCT is the better, but there are often financial and practical restraints that can limit the scope of research.

What did the research involve?

The research included 80 adults with ADHD (aged 16 or over) who were referred to the trial via public services, private clinicians, or were self-referred based on advertisements. They were then randomised to eight weeks of treatment with either micronutrients or placebo.

The trial was double-blind, meaning that neither participants nor researchers knew which tablets were being taken. Both groups took 15 capsules per day in three doses of five capsules, with the EMPowerplus micronutrient formula and placebo being identical in appearance.

Diagnoses of ADHD were based on valid diagnostic criteria. Participants had to be free from any psychiatric medications for at least four weeks ("talking therapies" were allowed).

More than half the sample had a history of taking psychiatric medications, which included antidepressants and stimulants. People with other mental health conditions, such as depression or bipolar disorder, were included.

Participants were assessed by psychologists at the study start, weeks one, two, four and six, and at the end of the study in week eight. Assessments at each point included:

change from baseline in ADHD symptoms and global change in functioning (for instance, from other psychiatric symptoms), both assessed on the Clinical Global Impression – Improvement (CGI-I) Scale

severity of symptoms of depression, assessed on the Montgomery-Åsberg Depression Rating Scale (MADRS)

general functioning on the Global Assessment of Functioning (GAF) scale

At baseline and the end of the study, the people with ADHD were also assessed on two other scales:

the Connors Adult ADHD Rating Scale (CAARS) – Observer: Screening Version (CAARS-O:SV), which gives the clinician's impression of functioning on four subscales measuring ADHD symptoms of inattention, hyperactivity, impulsivity and total symptoms over the previous eight weeks

At eight weeks, the participants themselves and someone who knew them well (such as a partner or parent) also completed self-report and observer CAARS scales.

The main outcomes of interest were changes in CAARS, CGI and MADRS scores.

What were the basic results?

The trial was completed by 90% of people in the micronutrient group and 95% in the placebo group.

People in the micronutrient group had a statistically significant greater improvement on the CGI-I scale: a 0.6 point greater decrease compared with placebo in ADHD symptom score, and 0.7 point greater decrease for global functioning.

On the CAARS scales, there was significantly greater improvement in the micronutrient group on the self- and observer-rated assessments (respectively, 6.7 and 5.1 points greater decrease than placebo), but not on the clinician's assessment (two points lower than placebo).

There was no significant difference between groups in change in MADRS scores.

Of the other outcomes, people in the micronutrient group had significantly greater improvement in general functioning on the GAF scale, but showed no differences from placebo in psychological functioning on the LIFE-RIFT scale.

There were no group differences in adverse events.

How did the researchers interpret the results?

The researchers conclude that their study "provides preliminary evidence of efficacy for micronutrients in the treatment of ADHD symptoms in adults, with a reassuring safety profile".

Conclusion

This RCT, assessing the effects of a micronutrient formula compared with placebo in 80 adults with ADHD, has various strengths in its design. These include:

the fact it was double blind, with neither participants nor researchers knowing which group they were assigned to

the use of valid diagnostic criteria

assessments were carried out regularly on a range of recognised assessment scales during the course of the trial

There are, however, some points to bear in mind when considering the results:

While the micronutrient formula had significant benefits over the placebo group on a few assessment scales, the point difference between groups was fairly small. It is difficult to know whether this would have a meaningful effect on the person's overall functioning in everyday life.

The trial has only assessed the effects up to eight weeks. The safety and effectiveness of taking this micronutrient formula in the longer term is unknown.

The trial was fairly small at 80 participants, and studies with larger groups of adults would be useful. However, the researchers did calculate beforehand that they would be able to detect clinically significant differences between the groups, with at least 36 people in each group.

The study has only compared the micronutrient formula with an inactive placebo. We don't know how it compares with other standard pharmacological or psychological treatments for ADHD.

The current treatment involved taking 15 capsules per day – people with ADHD may be unable or unwilling to take so many tablets every day.

The results cannot be generalised to children with ADHD.

This is a well-conducted RCT, but, as the researchers say, it provides preliminary evidence for the efficacy and safety of micronutrients in the treatment of ADHD symptoms in adults. Further study is needed.

If you are an adult currently being prescribed medication for ADHD, we would not recommend that you stop taking that medication in favour of vitamins. If you are having problems tolerating your medication, you should discuss this with the doctor in charge of your care.